Device for controlling flowing media

ABSTRACT

A valve for controlling flowing media, in particular suction air used in connection with suction heads or the like, in which closing diaphragms ( 17, 18 ) made from elastically deformable material are disposed within a valve housing ( 10 ) and are subjected to the action of compressed air via actuating lines ( 14, 15 ) in the closing or blocking direction, such that when each diaphragm ( 17, 18 ) moves into an open position, a subatmospheric pressure is generated on the side ling opposite the closing side.

BACKGROUND OF THE INVENTION

1. Technical Field

The invention relates to a device for the control of flowing media, inparticular a vacuum valve, having closing elements, movable within avalve housing, for valve apertures and having lines adjoining the valvehousing, specifically a supply line leading to a (vacuum) pump and aconsumer line or suction line leading to a consumer.

2. Prior Art

Valves for flowing media, in particular compressed air or vacuum, are inmany cases equipped with a rigid closing element movable within a valvehousing. This is customarily spring-loaded in one direction, for examplein the closing direction. As a result, opening and closing movements aresluggish, so that short cycle times are not possible in the long term.

BRIEF SUMMARY OF THE INVENTION

It is an object of the invention to propose a valve which permits asimple design and actuation of closing elements and is efficient in thelong term.

To achieve this object, the (vacuum) valve according to the invention ischaracterized in that at least one closing element is formed as anelastically deformable shaped piece, in particular as an elasticdiaphragm, which can be moved into an open or a closed position byreason of elastic deformation by being subjected to the action of apressure medium.

The diaphragm, as a closing element, is sealingly clamped along anannular circumferential edge and can be deformed by being subjectedunilaterally to the action of a pressure medium, in particular ofcompressed air, until it comes to bear on a valve seating.

The vacuum valve according to the invention is preferably employed forthe controlling of air in lifting heads with suction elements to pick uparticles. The vacuum valve is particularly suitable for controlling thevacuum at individual suction heads of a suction lifter, as isillustrated for example in U.S. Pat. No. 5,666,786.

A special feature of the invention lies in the concept of piloting ofthe valve. The use of a pilot valve ensures that subatmospheric pressureis always active when the (two) diaphragms are switched over.Specifically, the diaphragms are each deformed into an open position bysubatmospheric pressure and into the closed position by compressed air.As a result, very rapid working cycles of the valve are possible.

According to an advantageous embodiment of the vacuum valve, a flow pipeis positioned within the housing, one diaphragm being assigned as aclosing element to each of its two ends. The diaphragms are suppliedwith compressed air from the central compressed air supply of the(packaging) machine. As a result of the actuation of one or the otherdiaphragm, and closing of one or the other end of the flow pipe causedthereby, a suction line leading to the lifting head or to the suctionheads is connected to a supply line leading to the vacuum pump or thesuction line of the suction heads is vented.

BRIEF DESCRIPTION OF THE DRAWINGS

Further details of the invention relate to the construction and mode ofoperation of the valve. An example of embodiment thereof is described indetail below with reference to the drawings, in which:

FIG. 1 shows a (vacuum) valve in vertical section,

FIG. 2 shows the valve according to FIG. 1 in a changed open or closedposition.

FIG. 3 shows a vertical section through the valve in a sectional planeIII—III from FIG. 1, and

FIG. 4 shows a horizontal section through the valve in the sectionalplane IV—IV from FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The valve illustrated as an example of embodiment has a cuboid valvehousing 10. This is adjoined on various sides by supply lines andactuating lines. Affixed to the underside of the valve housing 10 is asupply line 11 which leads to a vacuum pump 12 and accordingly is infunctional terms a suction line. A consumer line, specifically a suctionline 13, adjoins a transversely lying, upright lateral surface and inthe preferred example of embodiment leads to a suction head of a suctionlifter (not shown) of a packaging robot. Actuating lines 14, 15 forvalve and closing elements are affixed to mutually opposite (upright)lateral surfaces. These are compressed air lines. In the region of anupper side a compensation line 16 is connected to the valve housing 10.

Formed within the valve housing 10 are passage apertures or flowpassages that can be blocked by closing elements. These closing elementsare in the present case in the form of diaphragms 17, 18 made fromelastically deformable or extensible material, for example from rubberor plastic. The disc-shaped diaphragms 17, 18 are sealingly and fixedlysecured along an outer edge. An inner, central region is left free. Toactuate a diaphragm 17, 18 as a closing element, the diaphragm 17, 18 issubjected on one (outer) side to the action of a flowing pressuremedium, specifically compressed air (arrows 19). As a result, swellingdeformation of the diaphragm 18 in question takes place until it comesto bear on a valve seating 20 or 21. The valve seating 20, 21, in theform of an annular circle with a rounded surface, is sealed all aroundby the diaphragm 17, 18. The compressed air to actuate the diaphragm 17,18 is fed through the actuating line 14, 15, through the actuating line15 to the diaphragm 18 in the position shown in FIG. 1.

The valve housing 10 consists of a core piece 22 and two lateral coverplates 23, 24. The latter serve first to fix the diaphragms 17, 18 onthe core piece 22. For reliable securing, the cover plates 23, 24 on theone hand and the core piece 22 on the other form a tongue-and-grooveconnection 25 for the diaphragms.

In the region of the covering plates 23, 24, the actuating lines 14, 15adjoin the valve housing 10 (centrally) and so form the pressure sidefor the actuation of the diaphragms 17, 18.

The core piece 22 has a plurality of flow passages and line connections.The supply line 11, the suction line 13 and the compensation line 16directly adjoin the core piece 22. A flow pipe 26 is formed within thelatter, centrally and in the transverse direction. This flow pipe 26positioned transversely to the supply line 11 forms at the ends thevalve seatings 20, 21 adjacent to the diaphragms 17, 18. The consumerline, specifically the suction line 13, adjoins the flow pipe 26 via apassage piece 27 at the longitudinal centre (FIG. 4). The ends of theflow pipe 26, in other words the valve seatings 20, 21, lie at adistance from the diaphragm 17, 18 when the latter is relaxed, so thatin the open position of the respective closing element an open flowpassage 28 (FIG. 1) or 29 (FIG. 2) is formed between diaphragm 17, 18and flow pipe 26. As a result of the design and arrangement of the flowpipe 26 within the housing an annular duct 30 is additionally formed atthe outside of the flow pipe 26, this being free even when the diaphragm17 is closed and connecting the compensation line 16 to the supply line11 (FIGS. 2 and 3).

The actuation of the diaphragms 17, 18 can be controlled by a pilotvalve 31. This is a 4/2-way valve. The actuating lines 14, 15 areconnected to the pilot valve 31. Furthermore, a central compressed airline 32 leads from a compressed air source, in particular a centralcompressed air supply on the machine side, to the pilot valve 31.Finally, the compensation line 16 is also connected to the pilot valve31.

In the position shown in FIG. 1, the actuating line 15 for the diaphragm18 is connected via the pilot valve 31 to the compressed air line 32.The diaphragm 18 is deformed by means of compressed air (arrows 19) intothe closed position.

In this position of the pilot valve 31, the actuating line 14 isconnected to the compensation line 16. Via the flow passage 28, aconnection to the supply line 11 and hence to the vacuum pump 12 isformed. Via the actuating line 14, a vacuum or subatmospheric pressureis transmitted in this manner to the outside of the diaphragm 17, withthe consequence that the switching operation, specifically the return ofthe diaphragm 17 from a closed position (FIG. 2) to the open position(FIG. 1) is assisted by subatmospheric pressure on the free side.

Moreover, in the position shown in FIG. 1, the consumer line, in otherwords the suction line 13, is connected via the flow pipe 26 and theflow passage 28 to the subatmospheric pressure source, specifically viathe supply line 11. In this position, then, the suction heads aresubjected to the action of subatmospheric pressure.

By adjusting the pilot valve 31 into the position shown in FIG. 2, theactuating line 14 is connected to the compressed air source or to thecompressed air line 32. The diaphragm 17 is pressed against theneighbouring valve seating 20, while simultaneously the diaphragm 18returns into the open position, bearing on the cover plate 24. Thisopening operation is assisted by the fact that the actuating line 15 isconnected via the compensation line 16 and the annular duct 30 to thevacuum pump 12, in other words subatmospheric pressure is generated onthe back of the diaphragm 18.

As a result of the opening of the diaphragm 18, a ventilation port33—disposed on the upper side of the core piece 22—is exposed. This isnow connected via the flow passage 29 and the flow pipe 26 to theconsumer line, in other words to the suction line 13. This isaccordingly vented, and the connected suction heads release the articlepicked up.

The design of the valve and/or the disposition of the elasticallydeformable closing elements—diaphragms 17, 18—has the result of ensuringthat the latter are always loaded in the closed position on the closingside, in other words on the side facing the valve seating 20, 21, withsubatmospheric pressure, so that no compressive forces counteract theclosing force exerted by compressed air from the actuating lines 14, 15.

List of references

10 Valve housing

11 Supply line

12 Vacuum pump

13 Suction line

14 Actuating line

15 Actuating line

16 Compensation line

17 Diaphragm

18 Diaphragm

19 Arrow

20 Valve seating

21 Valve seating

22 Core piece

23 Cover plate

24 Cover plate

25 Tongue-and-groove connection

26 Flow pipe

27 Passage piece

28 Flow passage

29 Flow passage

30 Annular duct

31 Pilot valve

32 Compressed air line

33 Ventilation port

What is claimed is:
 1. A valve having a valve housing (10), valveapertures, and elastic diaphragms (17, 18) acting as movable closingelements for the valve apertures, in which the elastic diaphragms (17,18) are actuated by a pressure-exerting medium, comprising: a. a supplyline (11) connecting the valve housing (10) to a vacuum pump (12); b. asuction line (13) connecting the valve housing (10) to a suction head;c. a ventilation port (33) through the valve housing (10) allowing fluidcommunication between the interior of the valve housing (10) and theexterior of the valve housing (10); d. two valve seats (20, 21) withinthe valve housing (10) cooperating respectively with the valveapertures, each of the two valve seats (20, 21) having one of theelastic diaphragms (17, 18) respectively as a closure element; and e.two actuating lines (14, 15) cooperating respectively with the elasticdiaphragms (17, 18), each of the two actuating lines (14, 15) allowingfluid communication between the elastic diaphragms (17, 18) respectivelyand the pressure exerting medium, wherein when the elastic diaphragms(17, 18) are in an undeformed position the elastic diaphragms (17, 18)are in an opened position and do not abut the respective valve seats(20, 21), and when the elastic diaphragms (17, 18) are in a deformedposition the elastic diaphragms (17, 18) are in a closed position andabut the respective valve seats (20, 21); and wherein when thepressure-exerting medium is applied via a first of the two actuatinglines (14, 15) to one of the elastic diaphragms (17, 18), the one of theelastic diaphragms (17, 18) is deformed into the closed position,whereby when a first of the two elastic diaphragms (17, 18) is in theopened position, a second of the two elastic diaphragms (17, 18) is inthe closed position and a connection between the supply line (11) andthe suction line (13) within the valve housing (10) is open, and whenthe second of the two elastic diaphragms (17, 18) is in the openedposition, the first of the two elastic diaphragms (17, 18) is in theclosed position and the connection between the supply line (11) and thesuction line (13) is closed and a connection between the suction line(13) and the ventilation port (33) is open.
 2. The valve according toclaim 1, characterized in that the supply line (11) connects a source(12) of subatmospheric pressure to the valve housing (10) in order totransfer the subatmospheric pressure to the suction line (13), whereinthe subatmospheric pressure transferred by the supply line (11) to afirst side of the first of the elastic diaphragms (17, 18) and thepressure-exerting medium from one of the two actuating lines (14, 15)applied to a second side of the first of the elastic diaphragms (17, 18)act on the first of the elastic diaphragms (17, 18) in order to deformthe first of the elastic diaphragms (17, 18) into the closed position.3. The valve according to claim 2, characterized in that the suctionline (13) is connected to a flow pipe (26) to supply a vacuum to asuction head of a lifting device, and in that the flow pipe (26) isconnected to the supply line (11) to a source (12) of subatmosphericpressure when a first of the elastic diaphragms (18) is in the closedposition and the second of the elastic diaphragms (17) is in the openedposition.
 4. The valve according to claim 2, characterized in that whenone of the elastic diaphragms (18) is in the opened position, thesuction line (13) is connected via a flow pipe (26) to the ventilationport (33).
 5. The valve according to claim 2, characterized in that thesource (12) of subatmospheric pressure is the vacuum pump.
 6. The valveaccording to claim 1, further comprising a flow pipe (26) formed in thevalve housing (10), wherein the flow pipe (26) has two ends both ofwhich are formed as the valve seats (20, 21) with each of the valveseats (20, 21) lying centrally opposite a relevant one of the elasticdiaphragms (17, 18).
 7. The valve according to claim 6, characterized inthat the flow pipe (26) is adjoined in the transverse axial direction byat least one suction line (13).
 8. The valve according to claim 6,further comprising a flow channel (28, 29) that is open when therelevant one of the elastic diaphragms (17, 18) is in the openedposition, the flow channel (28, 29) being formed between the two ends ofthe flow pipe (26) and the relevant one of the elastic diaphragms (17,18).
 9. The valve according to claim 8, characterized in that the flowpipe (26) is adjoined in the transverse axial direction by at least onesuction line (13).
 10. The valve according to claim 6, furthercomprising a compensation line (16) permanently connected to the supplyline (11) and leading to the source of subatmospheric pressure (12)proximal to the outside of the flow pipe (26).
 11. The valve accordingto claim 10, characterized in that the supply line (11) is connected tothe source (12) of subatmospheric pressure via an annular duct (30). 12.The valve according to claim 6, characterized in that: a. the elasticdiaphragms (17, 18) are alternately subjected to the action of thepressure-exerting medium; b. one of the two actuating lines (14, 15) isassigned to each of the elastic diaphragms (17, 18) to transmit thepressure-exerting medium to the respective assigned elastic diaphragm(17, 18); c. the pressure-exerting medium is fed by the respective oneof the two actuating lines (14, 15) to the respective assigned elasticdiaphragm (17, 18) on a side of the respective assigned elasticdiaphragm (17, 18) facing away from the valve seat (20, 21); and d. theactuating lines (14, 15) are connected to a common pressure-exertingmedium source (32).
 13. The valve according to claim 12, characterizedin that the two actuating lines (14, 15) are connected to thepressure-exerting medium source (32) via a pilot valve (32).
 14. Thevalve according to claim 12, characterized in that the pressure-exertingmedium (32) is a compressed air source supplied through a compressed airline.
 15. The valve according to claim 1, characterized in thatsubatmospheric pressure is applied on a first side of the elasticdiaphragms (17, 18) through a respective one of the two actuating lines(14, 15), the subatmospheric pressure being appropriately applied bypositioning a pilot valve (31) in a manner such that the respective oneof the two actuating lines (14, 15) is connected to a source (12) ofsubatmospheric pressure via a compensation line (16).
 16. The valveaccording to claim 1, characterized in that when the connection betweenthe supply line (11) and the suction line (13) is interrupted by anabutment of the first of the elastic diaphragms (17) on the respectivevalve seat (20), the actuating line (15) for the second of the elasticdiaphragms (18) is connected within the valve housing (10) to the supplyline (11) such that subatmospheric pressure is conveyed via theactuating line (15) to a side of the second of the elastic diaphragms(18) facing away from the respective valve seat (21).
 17. The valveaccording to claim 16, further comprising a flow pipe (26) formed withinthe valve housing (10), characterized in that the valve seats (20, 21)are annular, are formed at each of two ends of the flow pipe (26), thevalve seats (20, 21) lying centrally opposite to the elastic diaphragms(17, 18), wherein the elastic diaphragms (17, 18) are disposed at adistance from a respective one of the valve seats (20, 21) when theelastic diaphragms (17, 18) are in the opened position and the elasticdiaphragms (17, 18) abut the respective one of the valve seats (20, 21)when the elastic diaphragms are in the closed position.
 18. The valveaccording to claim 17, wherein the suction line (13) is joined to theflow pipe (26) in a transverse axial direction, and the flow pipe (26)is connected to the supply line (11) by a flow channel (28) when one ofthe valve seats (20) is open.
 19. The valve according to claim 1,wherein the two actuating lines (14, 15) are connected to a common pilotvalve (31), each of the two actuating lines (14, 15) is connected to apressure line (32) when the pilot valve is in a first position andconnected to a compensation line (16) when the pilot valve is in asecond position, the compensation line (16) is further connected to thevalve housing (10) and communicates with the supply line (11) and thevacuum pump (12) for conveying negative pressure to a side of at leastone of the elastic diaphragms (17, 18) facing away from the respectivevalve seats (20, 21).
 20. The valve according to claim 19, wherein thevalve housing (10) further comprises a core section (22) and coverplates (23, 24) disposed on opposite sides of the core section (22),wherein the elastic diaphragms (17, 18) span between the core section(22) and the associated cover plates (23, 24), and each of the twoactuating lines (14, 15) is connected to one or the other of the coverplates (23, 24).
 21. The valve according to claim 20, wherein a flowpipe (26) is arranged centrally within the core section (22) and isdisposed in a transverse axial direction to the supply line (11) and tothe compensation line (16).